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Sat Mar 30, 2024 7:23 am

After 4 years of cruising Montana roads as my daily driver and my road-trip-confidant, my 1.8L FI Type 4 (AW) bumping 20k on the rebuild is showing signs of catastrophic failure.

I change the oil and adjust the valves every 3000-5000 miles and always run premium gas, ethanol-free when possible.

I would say 6 months ago I noticed a humming sound, but didn't have any other symptoms. The sound eventually got louder. Last month I noticed that on a cold February morning, it fired right up idled like it had been running for the last hour, which I thought was unusual, but still thought it could have been a symptom of the pending valve adjustment that I needed to do. When I got around to my valve adjustment on Wednesday, I decided to pull off the alternator belt and see if I could get rid of the humming sound that's become way louder. I haven't noticed it which I'm embarrassed about, because this is my daily driver that I trust so much. However, when I pulled of the belt, the sound did not go away. At this point, I called my VW guru friend Randy and asked for his help.

It didn't take 30 seconds for Randy to diagnose the possible issue. The camshaft gear is coming loose from the camshaft.

I will post a video later this morning of the sound, but I'm getting ready to drop[ the engine and split the case. Hopefully, I can replace the camshaft, lifters, seals, and get it back together for summer driving.

Sat Mar 30, 2024 7:52 am

Sawyer2 wrote: It didn't take 30 seconds for Randy to diagnose the possible issue. The camshaft gear is coming loose from the camshaft.
i'd take this for what it is: an over-the-phone diagnostic.
you could confirm this "fairly easily" by removing the oil pump.
lots of things can make a humming sound.
in my experience, the cam and gear are not one of them.

also, ethanol free is good, but premium gas should not be needed.

Sat Mar 30, 2024 4:43 pm

Humming is an interesting way of describing a loose cam sound.

You'll hear the engine about ten seconds in.

I drove for about a thousand miles with that sound. One day taking off from a stop sign, I heard the most horrendous grind. The loose gear had finally ruined the cam thrust bearing. 8)

Mon Apr 08, 2024 4:20 pm

That's exactly what my bus sounds like.

https://www.youtube.com/watch?v=48OWboklqM0

Here are a few pictures of my cam and cam bearings.

Tue Apr 09, 2024 8:54 am

Tue Apr 09, 2024 8:36 pm

New bearings don’t match the old ones. The old cam gear has a N2 stamp on it as well. Anyone know what that might be?

Wed Apr 10, 2024 6:34 am

If you look at the Silverline box, it has two sets of numbers, one on the box, and a sticker added by the distribution center. I wonder, if these bearings are mislabeled, and I have the incorrect ones.

The box says 021 198 541T

The Pacific Parts International label says 021 198 541S

What the building installed 4 years ago:

Thu Apr 11, 2024 3:26 am

I've seen that happen a couple times where an engine was slapped together without checking clearances. Cam thrust bearings are almost always way too tight at the thrust surface now, especially Silverlines. That is exactly what I've seen when they just get snapped in the case without checking. It will grind away the surface on the bearing till it breaks off. Over agressive sanding to fit could always do this I suppose. It's why my cam always gets a gentle smack back and fourth before any sanding. Many times it's enough to get in spec.

Mon Apr 15, 2024 10:55 am

Some cams can have a rough surface on the thrust that needs polished.